Quick Facts
- Sample: Blood drawn from arm vein
- Fasting: Not required
- Turn-around: 2–5 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Skip the doctor's office – order online and visit any lab location
- Early morning convenience – best tested between 7-10 AM for accurate results
- Comprehensive hormone insight – measures key pituitary hormone affecting stress response
- Confidential results – private access to your hormone levels
- Fast turnaround – results in 2-5 business days
Who Is This Test For?
- Chronic fatigue sufferers experiencing unexplained exhaustion despite adequate rest
- Weight change concerns with sudden unexplained weight gain or loss
- Stress-related symptoms including muscle weakness, mood changes, or sleep issues
- Blood pressure irregularities with high or low readings of unknown cause
- Skin changes including unusual pigmentation, stretch marks, or easy bruising
- Hormone monitoring for those managing existing adrenal or pituitary conditions
How It Works – Just 3 Steps
- Order online – select your test and schedule a lab visit at your convenience
- Quick blood draw – visit any lab location for a simple arm vein blood sample
- Receive results – access your confidential results online within 2-5 business days
FAQ
What does ACTH measure in my blood? ACTH is a hormone from your pituitary gland that signals your adrenal glands to produce cortisol, essential for stress response and metabolism.
Why is morning testing important? ACTH levels naturally fluctuate throughout the day, with highest levels in early morning, making 7-10 AM testing most accurate.
What conditions can this test help identify? This test helps diagnose Cushing's disease, Addison's disease, secondary adrenal insufficiency, and pituitary disorders.
Do I need to stop any medications before testing? Avoid steroid medications and biotin supplements for 12-48 hours before testing if medically safe to do so.
How accurate is this test? When paired with cortisol testing, ACTH has up to 97% sensitivity for detecting primary adrenal insufficiency (StatPearls 2023).
What if my results are abnormal? Abnormal results require medical consultation for proper interpretation and potential follow-up testing or treatment planning.
More Details
What is the purpose of this test?
The ACTH blood test measures adrenocorticotropic hormone levels to diagnose disorders affecting your adrenal or pituitary glands. ACTH signals your adrenal glands to produce cortisol, a crucial hormone for stress response, metabolism, and immune function (Cleveland Clinic 2025). When cortisol levels are abnormal, measuring ACTH helps determine whether the problem originates in your pituitary gland or adrenal glands.
This test is essential for diagnosing conditions like Cushing's disease, Addison's disease, secondary adrenal insufficiency, and hypopituitarism. Healthcare providers often pair ACTH testing with cortisol measurements because these hormones typically change in opposite directions, providing clearer diagnostic information (Mayo Clinic 2020).
Who would benefit from this test?
Individuals experiencing symptoms of hormonal imbalance should consider ACTH testing. Those with severe fatigue, unexplained weight changes, unusual skin pigmentation, or blood pressure irregularities may have underlying adrenal or pituitary dysfunction (Mount Sinai 2024).
People managing existing adrenal or pituitary conditions benefit from regular ACTH monitoring to track treatment effectiveness. Additionally, those with family history of endocrine disorders or taking long-term steroid medications may want periodic screening to detect early hormonal changes.
When should I order an Adrenocorticotropic Hormone (ACTH) Blood Test?
Order this test if you experience persistent symptoms suggesting hormonal imbalance. Symptoms of excess cortisol include sudden weight gain, fat accumulation in shoulders, purple stretch marks, easy bruising, increased body hair, muscle weakness, and severe acne.
Symptoms of insufficient cortisol include sudden weight loss, nausea, vomiting, abdominal pain, dizziness, unusual skin darkening, salt cravings, and chronic fatigue (MedlinePlus 2023). Schedule testing if these symptoms persist despite lifestyle changes or if your healthcare provider recommends monitoring for existing conditions.
How do I interpret the results?
ACTH Level: 10–60 pg/mL (morning)
- What it means: Normal range
- Typical action: No immediate action needed
ACTH Level: Below 10 pg/mL
- What it means: Possible adrenal or pituitary disorder
- Typical action: Medical evaluation recommended
ACTH Level: Above 60 pg/mL
- What it means: May indicate Cushing's disease or adrenal insufficiency
- Typical action: Further testing usually required
ACTH Level: Extremely high (>200 pg/mL)
- What it means: Possible ectopic ACTH syndrome
- Typical action: Urgent medical consultation
Early detection and management of adrenal disorders can reduce mortality rates by up to 7 times (Endocrine Society 2016).
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
Schedule your test between 7-10 AM for most accurate results due to natural hormone fluctuations. Avoid glucocorticoid medications like prednisone for 12-48 hours before testing if medically safe (UCSF Health).
Stop biotin supplements at least 12 hours before testing as they can interfere with results. Most people don't need to fast, but follow any specific instructions provided. Inform the lab about current medications, especially steroids or hormone treatments that might affect results.
How often should I get tested?
- Initial symptoms evaluation: Once, with follow-up as needed
- Monitoring treatment response: Every 3–6 months initially
- Stable chronic condition: Every 6–12 months
- Medication adjustments: 4–8 weeks after changes
- Routine screening (high-risk): Annually or as recommended
Why early detection matters
Adrenal and pituitary disorders can significantly impact your quality of life if left untreated. Addison's disease affects approximately 100-140 per million people in the U.S. and can lead to life-threatening adrenal crisis without proper management (Endocrine Society 2016).
Cushing's syndrome affects about 10-15 per million people annually and can cause serious complications including diabetes, osteoporosis, and cardiovascular disease. Early detection through ACTH testing enables prompt treatment, preventing progression to more severe complications and improving long-term health outcomes.
Related tests you may consider
Cortisol Blood Test – Essential companion test that measures your body's primary stress hormone, almost always ordered with ACTH for complete evaluation.
24-Hour Urine Free Cortisol – Assesses cortisol production over a full day, particularly useful for diagnosing Cushing's syndrome and monitoring treatment.
Aldosterone:Renin Blood Test – Evaluate additional adrenal hormones important for blood pressure regulation and distinguishing types of adrenal insufficiency.
